The invention relates to a process and a device for manufacturing corrugated board, in particular, quintuple or double-double corrugated board.
For the assembly and gluing of at least three individual constituent webs, as is required, for example, in the manufacture of quintuple, i.e. so-called double-double corrugated board, up to this point, as a rule, a triple preheater has been used as an independent unit as well as a subsequently disposed double glue application mechanism, likewise used as an independent unit. With the aid of the glue application mechanism, two out of three webs to be glued are coated with glue on one surface and are supplied to a press device, together with another web that has not had glue applied to it. In other words: after glue is applied to two out of three webs to be glued together, they are assembled with the third web at a single point and the mutually opposing surfaces of the individual constituent webs are pressed against one another. As a rule, the assembly of the constituent webs takes place in a gluing machine with two inlet rolls oriented perpendicular to the web travel, by means of which the individual constituent webs are supplied to a heating section that serves to harden the glue and dry the finished web. In order to achieve a rapid gelling of the glue and thereby a rapid wet gluing after the assembly of the webs, it is necessary to heat at least the webs to be glued before the application of the glue. To this end, a preheater with a number of preheating cylinders is usually disposed before the double glue application mechanism.
With this known process and this known device for producing multilayer corrugated board, in particular, quintuple or double-double corrugated board, however, it is disadvantageous that relatively large web lengths are required between the glue application points of the double glue application mechanism and the assembly point of the individual constituent webs in the gluing machine. Depending on the temperature of the webs supplied to the gluing mechanism, this brings about the danger that too much moisture is extracted from the glue before the start of the gelling process, which has a disadvantageous effect on the adhesion strength of the glue when the individual constituent webs are brought together. Also, due to the size of the gluing mechanism, it is only possible--if at all--to shorten the web length of all of the constituent webs between the glue application point and the assembly point to the desired size when there is a large structural expenditure. Furthermore, the relatively large distances between the preheaters and the web assembly point results in an intense cooling of the individual webs, which at the same time leads to the fact that the web does not have the optimal temperature sought for the gluing.